Liquid crystal display to increase side view visibility

ABSTRACT

Provided is a liquid crystal display to provide improved transmittance and visibility includes a first substrate; a first switching element and a second switching element formed on the first substrate configured to be switched by the same signal; a first subpixel electrode connected to the first switching element; a second subpixel electrode connected to the second switching element; a third switching element connected to the second switching element; a third subpixel electrode connected to the third switching element; a second substrate; a common electrode formed on the second substrate; and a liquid crystal layer formed between the first substrate and the second substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of application Ser. No. 13/170,578,filed on Jun. 28, 2011, now issued as U.S. Pat. No. 8,941,793, andclaims priority to and the benefit of Korean Patent Application No.10-2010-0127627, filed on Dec. 14, 2010, which are incorporated byreference for all purposes as if fully set forth herein.

BACKGROUND

1. Field

The present invention relates to a liquid crystal display, and moreparticularly, to a liquid crystal display that has improvedtransmittance and visibility.

2. Discussion of the Background

Liquid crystal displays (LCD), may be composed of two display panelswith field generating electrodes, such as a pixel electrode and a commonelectrode, and a liquid crystal layer between the display panels. LCDsdisplay images by generating an electric field in the liquid crystallayer if voltage is applied to the field generating electrodes such thatthe liquid crystal molecules in the liquid crystal layer are aligned tocontrol polarization of incident light.

The conventional liquid crystal displays may include switching elementsconnected to the pixel electrodes and multiple signal lines, such asgate lines and data lines, to apply voltage to the pixel electrodes bycontrolling the switching elements.

Further, in the conventional liquid crystal displays, a verticallyaligned mode of liquid crystal display, in which the long axes of theliquid crystal molecules are arranged perpendicular to the displaypanel, without an electric field has been under the spotlight because ofthe large contrast ratio and the wide reference viewing angle. Thereference viewing angle may imply a viewing angle under a contrast ratioof 1:10 or a luminance reverse limit angle between grays.

A method of dividing one pixel into two subpixels and applying differentvoltages to the subpixels to provide a difference in transmittance hasbeen proposed in order to make the side visibility similar to the frontvisibility of the type of liquid crystal display. In this configuration,if different voltages are applied to the two subpixels through differentdata lines, double data driving circuits may be used. However, such aconfiguration may face cost increases in manufacturing.

A method of connecting the same data line to the two subpixels andreducing the voltage of one of the two subpixels by using a specificswitching element and a capacitor has been proposed to solve theproblem. However, the method has a problem of low transmittance to thesame aperture ratio.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the invention andtherefore it may contain information that may not constitute prior artthat may be already known in this country to a person of ordinary skillin the art.

SUMMARY

The present invention has been made in an effort to provide a liquidcrystal display having advantages of having high transmittance andimproved visibility.

Additional features of the invention will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention.

Exemplary embodiments of the present invention provide a liquid crystaldisplay including a first substrate; a first switching element and asecond switching element formed on the first substrate and configured tobe switched by the same signal; a first subpixel electrode connected tothe first switching element; a second subpixel electrode connected tothe second switching element; a third switching element connected to thesecond switching element; a third subpixel electrode connected to thethird switching element; a second substrate; a common electrode formedon the second substrate; and a liquid crystal layer formed between thefirst substrate and the second substrate.

Exemplary embodiment of the present invention provides a liquid crystaldisplay including a first substrate; a first gate line, a second gateline, and a data line formed on the first substrate; a first switchingelement and a second switching element connected to the first gate lineand the data line; a first subpixel electrode connected to the firstswitching element; a second subpixel electrode and a third subpixelelectrode connected to the second switching element; a firsttransforming capacitor formed between the second switching element andthe third subpixel electrode; a third switching element connected to thesecond switching element and configured to be switched by second gateline; a second transforming capacitor connected to the third switchingelement; a second substrate; a common electrode formed on the secondsubstrate; and a liquid crystal layer formed between the first substrateand the second substrate.

Exemplary embodiment of the present invention provide a liquid crystaldisplay including a first substrate; a first switching element and asecond switching element formed on the first substrate; a first liquidcrystal capacitor connected to the first switching element; a secondliquid crystal capacitor connected to the second switching element; athird switching element connected to the second switching element; and athird liquid crystal capacitor connected to the third switching element.

Exemplary embodiment of the present invention provide a liquid crystaldisplay including a first substrate; a first gate line, a second gateline, and a data line formed on the first substrate; a first switchingelement and a second switching element connected to the first gate lineand the data line; a first liquid crystal capacitor connected to thefirst switching element; a second liquid crystal capacitor and a thirdliquid crystal capacitor connected to the second switching element; afirst transforming capacitor formed between the second switching elementand the third liquid crystal capacitor; a third switching elementconnected to the second switching element and configured to be switchedby the second gate line; and a second transforming capacitor connectedto the third switching element.

It is to be understood that both foregoing general descriptions and thefollowing detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.Other features and aspects will be apparent from the following detaileddescription, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention, andtogether with the description serve to explain the principles of theinvention.

FIG. 1 is an equivalent circuit diagram of one pixel a liquid crystaldisplay according to an exemplary embodiment of the invention.

FIG. 2 is a layout view of a lower display panel of the liquid crystaldisplay according to an exemplary embodiment of the invention.

FIG. 3 is a graph showing voltage of each electrode if the liquidcrystal display is activated according to an exemplary embodiment of theinvention.

FIG. 4 is an equivalent circuit diagram of one pixel of a liquid crystaldisplay according to an exemplary embodiment of the invention.

FIG. 5 is a layout view of a lower display panel of the liquid crystaldisplay according to an exemplary embodiment of the invention.

FIG. 6 is a layout view of a lower display panel of a liquid crystaldisplay according to an exemplary embodiment of the invention.

FIG. 7 is a cross-sectional view of the liquid crystal display accordingto an exemplary embodiment of the invention, taken along the lineVII-VII′ of FIG. 6.

FIG. 8 is a cross-sectional view of the liquid crystal display accordingto an exemplary embodiment of the invention, taken along the lineVIII-VIII′ of FIG. 6.

FIG. 9 is a cross-sectional view of a liquid crystal display accordingto a modification of an exemplary embodiment of the invention, takenalong the line VIII-VIII′ of FIG. 6.

FIG. 10 is an equivalent circuit diagram of one pixel of a liquidcrystal display according to an exemplary embodiment of the invention.

FIG. 11 is a layout view of a lower display panel of the liquid crystaldisplay according to an exemplary embodiment of the invention.

FIG. 12 is a cross-sectional view of a liquid crystal display accordingto an exemplary embodiment of the invention, taken along the lineXII-XII′ of FIG. 11.

FIG. 13 is an equivalent circuit diagram of one pixel a liquid crystaldisplay according to an exemplary embodiment of the invention.

FIG. 14 is a layout view of a lower display panel of the liquid crystaldisplay according to an exemplary embodiment of the invention.

FIG. 15 is an equivalent circuit diagram of one pixel a liquid crystaldisplay according to an exemplary embodiment of the invention.

FIG. 16 is a graph showing a V-T curve at the front and the side of aliquid crystal display according to the related art.

FIG. 17 is a graph showing a V-T curve at the front and the side of aliquid crystal display according to an exemplary embodiment of theinvention.

FIG. 18 is a graph showing a V-T curve at the front and the side of aliquid crystal display according to an exemplary embodiment of theinvention.

FIG. 19 is a graph showing a V-T curve at the front and the side of aliquid crystal display according to an exemplary embodiment of theinvention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The present invention will be described more fully hereinafter withreference to the accompanying drawings, in which exemplary embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these exemplary embodiments areprovided so that this disclosure is thorough, and will fully convey thescope of the invention to those skilled in the art. It will beunderstood that when an element is referred to as being “on” or“connected to” or “coupled to” another element, it can be directly on,directly connected to, or directly coupled to the other element, orintervening elements may be present. In contrast, if an element isreferred to as being “directly on” or “directly connected to” or“directly coupled to” another element, no intervening elements arepresent. Throughout the drawings and the detailed description, unlessotherwise described, the same drawing reference numerals are understoodto refer to the same elements, features, and structures. The relativesize and depiction of these elements may be exaggerated for clarity,illustration, and convenience.

A liquid crystal display according to a first exemplary embodiment ofthe present invention is described first with reference to theaccompanying drawings.

FIG. 1 is an equivalent circuit diagram of one pixel a liquid crystaldisplay according to an exemplary embodiment of the invention. FIG. 2 isa layout view of a lower display panel of the liquid crystal displayaccording to an exemplary embodiment of the invention.

A liquid crystal display according to a first exemplary embodiment ofthe invention, as shown in FIG. 1, includes a first switching element Qaand a second switching element Qb, a first liquid crystal capacitor Clcaconnected to the first switching element Qa, a second liquid crystalcapacitor Clcb connected to the second switching element Qb, a thirdswitching element Qc connected to the second switching element Qb, and athird liquid crystal capacitor Clcc connected to the third switchingelement Qc.

The liquid crystal display according to the first exemplary embodimentof the invention may further include a first gate line GLn, a secondgate line GLn+1, and a data line DL. The first switching element Qa andthe second switching element Qb may be three terminal elements of a thinfilm transistor etc., connected to the first gate line GLn to beswitched by the same signal, and connected to the data line DL toreceive the same data signal. The third switching element Qc is a threeterminal element of a thin film transistor etc., and is connected to thesecond gate line GLn+1.

If gate-on voltage is applied to the first gate line GLn, the firstswitching element Qa and the second switching element Qb are turned onand the same data signal is applied through the data line DL, such thatthe first liquid crystal capacitor Clca and the second liquid crystalcapacitor Clcb are charged with similar or near identical voltage.Thereafter, if gate-on voltage is applied to the second gate line GLn+1,which is the next gate line, the third switching element Qc is turned onand some of the charged voltage of the second liquid crystal capacitorClcb are discharged to the third liquid crystal capacitor Clcc.Therefore, a difference in voltage is created between the first liquidcrystal capacitor Clca and the second liquid crystal capacitor Clcb. Asa result, the side visibility of the liquid crystal display can beimproved.

In the structure of the liquid crystal display according to the firstexemplary embodiment of the invention, as shown in FIG. 2, one or moreof first gate lines 121 a and second gate lines 121 b are provided on afirst substrate (not shown). In an example, the first substrate may bemade of transparent glass or plastic.

The first gate lines 121 a and second gate lines 121 b may transmit gatesignals and may extend transversely. The first gate lines 121 a and thesecond gate lines 121 b may be alternately disposed and gate-on voltagemay be sequentially applied to the first gate lines 121 a and the secondgate lines 121 b.

The first gate line 121 a includes one or more of first gate electrodes124 a and second gate electrodes 124 b, which protrude downward. Thefirst gate electrode 124 a and the second gate electrode 124 b may beconnected in one unit, such that they receive the same gate signalthrough the first gate line 121 a. The second gate line 121 b includesone or more of third gate electrodes 124 c protruding upward.

A gate insulating layer (not shown) may be formed on the first gatelines 121 a and second gate lines 121 b. A semiconductor island (notshown) may be formed on the gate insulating layer. The semiconductorisland may be disposed above the first gate electrode 124 a, second gateelectrode 124 b, and third gate electrode 124 c.

As shown further in FIG. 2, one or more data lines 171, a first sourceelectrode 173 a, a second source electrode 173 b, a third sourceelectrode 173 c, a first drain electrode 175 a, a second drain electrode175 b, and a third drain electrode 175 c are formed on the semiconductorand the gate insulating layer.

The data line 171 transmits a data signal and may extend longitudinallyto cross the first gate line 121 a and second gate line 121 b.

The first source electrode 173 a and the second source electrode 173 bprotrude from the data line 171 and may be connected in one unit, suchthat they receive the similar or near identical data voltage through thedata line 171. The first source electrode 173 a is formed in a U-shapeon the first gate electrode 124 a and the second source electrode 173 bis formed in a U-shaped on the second gate electrode 124 b.

The first drain electrode 175 a is spaced apart from the first sourceelectrode 173 a and has a bar-shaped end, with the first gate electrode124 a there between, in which the bar-shaped end is partially surroundedby the first source electrode 173 a bending in a U-shape.

The second drain electrode 175 b is spaced apart from the second sourceelectrode 173 b and has a bar-shaped end, with the second gate electrode124 b there between, in which the bar-shaped end is partially surroundedby the second source electrode 173 b bending in a U-shape. The other endof the second drain electrode 175 b is connected to the third sourceelectrode 173 c.

The third source electrode 173 c extends from the second drain electrode175 b, in a U-shape on the third gate electrode 124 c. The third drainelectrode 175 c is spaced apart from the third source electrode 173 cand has a bar-shaped end, with the third gate electrode 124 c therebetween, in which the bar-shaped end is partially surrounded by thethird source electrode 173 c bending in a U-shape.

The first source electrode 173 a may be formed in an inverse U-shape,the second source electrode 173 b in a U-shape open to the right, andthe third source electrode 173 c in a U-shape open to the right.Therefore, it may be possible to reduce a change in capacitance betweenthe gate electrodes (first gate electrode 124 a, second gate electrode124 b, and third gate electrode 124 c) and the source electrodes (firstsource electrode 173 a, second source electrode 173 b, and third sourceelectrode 173 c), even if an error occurs in the positions of the sourceelectrodes (first electrode 173 a, second electrode 173 b, and thirdsource electrode 173 c) due to a process deviation.

In an example, the first gate electrode 124 a, the first sourceelectrode 173 a, and the first drain electrode 175 a may constitute thefirst switching element (Qa in FIG. 1). The second gate electrode 124 b,the second source electrode 173 b, and the second drain electrode 175 bmay constitute the second switching element (Qb in FIG. 1). The thirdgate electrode 124 c, the third source electrode 173 c, the third drainelectrode 175 c may constitute the third switching element (Qc in FIG.1).

A passivation layer (not shown) is formed on the data line 171, thefirst source electrode 173 a, second source electrode 173 b, and thirdsource electrode 173 c, first drain electrode 175 a, second drainelectrode 175 b, and third drain electrode 175 c. The passivation layermay be made of an inorganic insulator or organic insulator, with a flatsurface. Further, the passivation layer may have a double layerstructure including a lower layer, which may be an inorganic layer, andan upper layer, which may be an organic layer, in order to keep the highinsulation of an organic layer, without damaging the exposed portion ofthe semiconductor.

A first contact hole 181 a exposing a portion of the first drainelectrode 175 a, a second contact hole 181 b exposing a portion of thesecond drain electrode 175 b, and a third contact hole 181 c exposing aportion of the third drain electrode 175 c are formed on the passivationlayer.

One or more first subpixel electrodes 191 a, second subpixel electrodes191 b, and third subpixel electrodes 191 c may be made of a transparentelectrode material, such as an ITO (Indium Tin Oxide) or an IZO (IndiumZinc Oxide) on the passivation layer. The first subpixel electrode 191 ais connected to the first drain electrode 175 a through the firstcontact hole 181 a, the second subpixel electrode 191 b is connected tothe second drain electrode 175 b through the second contact hole 181 b,and the third subpixel electrode 191 c is connected to the third drainelectrode 175 c through the third contact hole 181 c.

Although not shown, a common electrode may be provided on a secondsubstrate assembled with the first substrate, and a liquid crystal layermay be provided between the first substrate and the second substrate.

The first subpixel electrode 191 a and the second subpixel electrode 191b together with the common electrode on the second substrate and theliquid crystal layer there between respectively constitute first liquidcrystal capacitors (Clca in FIG. 1) and second liquid crystal capacitor(Clcb in FIG. 1). The liquid crystal capacitors as described here mayretain the applied voltage even after the first and second switchingelements Qa and Qb are turned off.

The third subpixel electrode 191 c constitutes a third liquid crystalcapacitor (Clcc in FIG. 1), together with the common electrode on thesecond substrate and the liquid crystal layer there between. Some of thevoltage stored in the second liquid crystal capacitor Clcb may bedischarged to the third liquid crystal capacitor Clcc, such that adifference in voltage may be created between the first liquid crystalcapacitor Clca and the second liquid crystal capacitor Clcb.

In this configuration, the third subpixel electrode 191 c is formedbetween the first gate line 121 a and the second gate line 121 b. Alight blocking member is formed on the second substrate, correspondingto the first gate line 121 a, second gate line 121 b, first switchingelement Qa, second switching element Qb, and third switching element Qc,and the third subpixel electrode 191 c. That is, the third subpixelelectrode 191 c may reduce the voltage of the second subpixel electrode191 b, but may not display an image by transmitting light.

The liquid crystal display according to the first exemplary embodimentof the invention may further include one or more of storage electrodelines 131 formed on the same layer as the first gate line 121 a andsecond gate line 121 b.

The storage electrode line 131 receives a reference voltage and mayextend substantially in parallel with and at a reference distance fromthe first gate line 121 a and second gate line 121 b. The storageelectrode line 131 may be positioned between the first gate line 121 aof a first pixel and the second gate line 121 b of a second pixel. Thestorage electrode line 131 may include a storage electrode 133, whichmay expand upward or downward. However, the shape and arrangement of thestorage electrode line 131 and the storage electrodes 133 may bemodified in various ways.

In the conventional technology, the third drain electrode 175 c and thestorage electrode 133 may be configured overlap to function as acapacitor that reduces the voltage of the second subpixel electrode 191b. However, this type of configuration may incur some problem in thatthe provided transmittance may be low, and the semiconductor ispositioned between the third drain electrode 175 c and the storageelectrode 133 to possibly generate a surface residual image, if theliquid crystal display is formed through a four-time photolithography.Further, there may be a problem in that the first gate line 121 a andthe third drain electrode 175 c overlap, which may possibly generateparasitic capacity, which may have an adverse effect on the image madeby the second subpixel electrode 191 b.

On the contrary, in the disclosed invention, the third subpixelelectrode 191 c may be formed such that the third liquid crystalcapacitor (Clcc in FIG. 1) functions as a capacitor to reduce thevoltage of the second subpixel electrode 191 b. Accordingly, it may bepossible to further improve the transmittance and reduce the surfaceresidual image, in comparison to the related art. In an example, thetransmittance may improve as much as 5%, if not more. Further, the firstgate line 121 a and the third drain electrode 175 c may be configured sothat do not overlap each other. As a result, it may be possible toprevent or reduce parasitic capacitance.

The first subpixel electrode 191 a and second subpixel electrode 191 bconstitute a storage capacitor by overlapping the storage electrode 133,which may help the first liquid crystal capacitor Clca and second liquidcrystal capacitor Clcb retain their voltage.

The voltage relationship that may be present if the liquid crystaldisplay of the first exemplary embodiment of the invention is activatedis described hereafter.

FIG. 3 is a graph showing voltage of each electrode if the liquidcrystal display is activated according to an exemplary embodiment of theinvention.

First, if a first gate signal V_GLn is supplied to the first gate line121 a, the voltage V_PX1 of the first subpixel electrode 191 a and thevoltage V_PX2 of the second subpixel electrode 191 b may be charged tosimilar or near identical levels. If a second gate signal V_GLn+1 issupplied to the second gate line 121 b, the voltage V_PX3 of the thirdsubpixel electrode 191 c may be increased to similar voltage level V_PX2of the second subpixel electrode 191 b, and the voltage V_PX2 of thesecond subpixel electrode 191 b and the voltage V_PX3 of the thirdsubpixel electrode 191 c may be decreased to a voltage level below thevoltage V_PX1 of the first subpixel electrode 191 a.

It can be seen that the voltage V_PX2 of the second subpixel electrode191 b and the voltage V_PX3 of the third subpixel electrode 191 c areclose at the point A, such that it can also be seen that the thirdsubpixel electrode 191 c may reduce the voltage V_PX2 of the secondsubpixel electrode 191 b, and also display an image. Using the thirdsubpixel electrode 191 c to display an image, without covering it with alight blocking member, in the second exemplary embodiment is describedhereafter.

A liquid crystal display according to the second exemplary embodiment ofthe invention is described hereafter in detail with reference to FIG. 4and FIG. 5.

FIG. 4 is an equivalent circuit diagram of one pixel of a liquid crystaldisplay according to an exemplary embodiment of the invention. FIG. 5 isa layout view of a lower display panel of the liquid crystal displayaccording to an exemplary embodiment of the invention.

As shown in FIG. 4, the liquid crystal display according to the secondexemplary embodiment of the invention may be similar in structure asillustrated in the circuit diagram as the liquid crystal displayaccording to the first exemplary embodiment, and as such will notdescribed. However, the second exemplary embodiment has a difference inthe layout view from the first exemplary embodiment, and this isdescribed in more detail with reference to FIG. 5.

In the structure of the liquid crystal display according to the secondexemplary embodiment of the invention, one or more of first gate lines121 a and second gate lines 121 b are formed on a first substrate (notshown), which may made of transparent glass or plastic, as shown in FIG.5.

The first gate line 121 a and the second gate line 121 b transmit gatesignals and may extend transversely. The first gate line 121 a and thesecond gate line 121 b may be alternately disposed and gate-on voltagemay be sequentially applied to the first gate line 121 a and the secondgate line 121 b.

The first gate line 121 a may include one or more first gate electrodes124 a and second gate electrodes 124 b, which may protrude upward anddownward, respectively. Also, the first gate electrode 124 a and thesecond gate electrode 124 b may receive the same gate signal through thefirst gate line 121 a. The second gate line 121 b may include one ormore third gate electrodes 124 c, which may protrude therefrom.

A gate insulating layer (not shown) may be further formed on the firstgate lines 121 a and the second gate lines 121 b. A semiconductor island(not shown) may be formed on the gate insulating layer. Thesemiconductor island may further be disposed above the first gateelectrode 124 a, the second gate electrode 124 b, and the third gateelectrode 124 c.

One or more data lines 171, a first source electrode 173 a, a secondsource electrode 173 b, a third source electrode 173 c, a first drainelectrode 175 a, a second drain electrode 175 b, and a third drainelectrode 175 c may be formed on the semiconductor and the gateinsulating layer.

The data line 171 transmits a data signal and may extend longitudinally,crossing the first gate line 121 a and the second gate line 121 b.

The first source electrode 173 a protrudes above the first gateelectrode 124 a from the data line 171, the second source electrode 173b protrudes above the second gate electrode 124 b from the data line171. Further, the first source electrode 173 a and the second sourceelectrode 173 b may be connected in one unit, such that they may receivethe same data voltage through the data line 171. The first sourceelectrode 173 a is formed in a U-shape on the first gate electrode 124 aand the second source electrode 173 b is formed in a U-shape on thesecond gate electrode 124 b.

The first drain electrode 175 a is spaced apart from the first sourceelectrode 173 a and has a bar-shaped end, with the first gate electrode124 a there between, in which the bar-shaped end is partially surroundedby the first source electrode 173 a bending in a U-shape.

The second drain electrode 175 b is spaced apart from the second sourceelectrode 173 b and has a bar-shaped end, with the second gate electrode124 b there between, in which the bar-shaped end is partially surroundedby the second source electrode 173 b bending in a U-shape. The other endof the second drain electrode 175 b is connected to the third sourceelectrode 173 c.

The third source electrode 173 c extends from the second drain electrode175 b, in a U-shape on the third gate electrode 124 c. The third drainelectrode 175 c is spaced apart from the third source electrode 173 cand has a bar-shaped end, with the third gate electrode 124 c therebetween, in which the bar-shaped end is partially surrounded by thethird source electrode 173 c bending in a U-shape.

In an example, the first gate electrode 124 a, the first sourceelectrode 173 a, and the first drain electrode 175 a may constitute thefirst switching element (Qa in FIG. 4). The second gate electrode 124 b,the second source electrode 173 b, and the second drain electrode 175 bmay constitute the second switching element (Qb in FIG. 4). The thirdgate electrode 124 c, the third source electrode 173 c, the third drainelectrode 175 c may constitute the third switching element (Qc in FIG.4).

A passivation layer (not shown) may be formed on various components,including the data line 171, the first source electrode 173 a, thesecond source electrode 173 b, and the third source electrode 173 c, thefirst drain electrode 175 a, the second drain electrode 175 b, and thethird drain electrode 175 c. The passivation layer may be made of aninorganic insulator or an organic insulator, with a flat surface.Further, the passivation layer may have a double layer structurecomposed of a lower layer, which may be an inorganic layer, and an upperlayer, which may be an organic layer, in order to keep the highinsulation of an organic layer and reducing the risk of damaging theexposed portion of the semiconductor.

A first contact hole 181 a exposing a portion of the first drainelectrode 175 a, a second contact hole 181 b exposing a portion of thesecond drain electrode 175 b, and a third contact hole 181 c exposing aportion of the third drain electrode 175 c may be formed on thepassivation layer.

One or more first subpixel electrode 191 a, second subpixel electrodes191 b, and third subpixel electrodes 191 c may be made of a transparentelectrode material, such as an ITO (Indium Tin Oxide) or an IZO (IndiumZinc Oxide), and formed on the passivation layer. The first subpixelelectrode 191 a is connected to the first drain electrode 175 a throughthe first contact hole 181 a. The second subpixel electrode 191 b isconnected to the second drain electrode 175 b through the second contacthole 181 b. The third subpixel electrode 191 c is connected to the thirddrain electrode 175 through the third contact hole 181 c.

The first subpixel electrode 191 a and the second subpixel electrode 191b are formed above and under the first gate line 121 a, respectively.Further, the second subpixel electrode 191 b and the third subpixelelectrode 191 c are formed above and under the second gate line 121 b,respectively. That is, the second subpixel electrode 191 b is formedbetween the first gate line 121 a and the second gate line 121 b. Inthis configuration, although the first subpixel electrode 191 a, thesecond subpixel electrode 191 b, the third subpixel electrode 191 c areshown having the same size, the invention is not limited thereto and maymake the size different.

Although not shown, a common electrode may be provided on a secondsubstrate. Further, the second substrate may be assembled with the firstsubstrate and a liquid crystal layer may be formed between the firstsubstrate and the second substrate.

The first subpixel electrode 191 a and the second subpixel electrode 191b, together with the common electrode on the second substrate and theliquid crystal layer there between, may constitute first liquid crystalcapacitors (Clca in FIG. 4) and second liquid crystal capacitor (Clcb inFIG. 4). The liquid crystal capacitors as described here may retain theapplied voltage even after the first and second switching elements Qaand Qb are turned off.

The third subpixel electrode 191 c, together with the common electrodeon the second substrate and the liquid crystal layer there between, mayconstitute a third liquid crystal capacitor (Clcc in FIG. 4). Some ofthe voltage stored in the second liquid crystal capacitor Clcb may bedischarged to the third liquid crystal capacitor Clcc, such that adifference in voltage may be created between the first liquid crystalcapacitor Clca and the second liquid crystal capacitor Clcb. As aresult, the voltage level of the second subpixel electrode 191 b and thevoltage level of the third subpixel electrode 191 c may be similar.

The liquid crystal display according to the second exemplary embodimentof the invention may further include one or more first electrode line131 a, second electrode line 131 b, and third storage electrode line 131c that are formed on the same layer as the first gate line 121 a and thesecond gate line 121 b.

The first storage electrode line 131 a, the second electrode line 131 b,and the third storage electrode line 131 c may receive reference voltageand may extend substantially in parallel with and at a referencedistance from the first gate lines 121 a and the second gate line 121 b.The storage electrode lines (first storage electrode line 131 a, thesecond storage electrode line 131 b, and the third storage electrodeline 131 c) may further include additional storage electrodes (firststorage electrode 133 a, second storage electrode 133 b, third storageelectrode 133 c, and fourth storage electrode 133 d,) which expandtherefrom.

In an example, the first storage electrode line 131 a may be formedabove the first subpixel electrode 191 a, the second storage electrodeline 131 b may overlap the center portion of the second subpixelelectrode 191 b, and the third storage electrode line 131 c may beformed under the third subpixel electrode 191 c.

The first storage electrode 133 a protrudes from the first storageelectrode line 131 a to partially overlap the left side and right sideof the first subpixel electrode 191 a.

The second storage electrode 133 b may be formed in parallel with thefirst gate line 121 a, overlapping the center portion of the firstsubpixel electrode 191 a. The second storage electrode 133 b connectsthe first storage electrode 133 a with the first storage electrode 133a, which may be at the left side and the right side of the firstsubpixel electrode 191 a, respectively.

The first storage electrode 133 a may partially overlap one of the leftside or the right side of the first subpixel electrode 191 a. The secondstorage electrode 133 b is connected to the first storage electrode 133a formed at any one side.

The third storage electrode 133 c protrudes from the second storageelectrode line 131 b, partially overlapping the left and right sides ofthe second subpixel electrode 191 b.

The fourth storage electrode 133 d protrudes from the third storageelectrode line 131 c, overlapping the left and right sides of the thirdsubpixel electrode 191 c.

Alternatively, the third storage electrode 133 c and the fourth storageelectrode 133 d may respectively partially overlap only one of the leftand right sides of the second subpixel electrode 191 b and thirdsubpixel electrode 191 c.

Further, the shape and arrangement of the storage electrode lines (firststorage electrode line 131 a, second storage electrode line 131 b, andthird storage electrode line 131 c) and the storage electrodes (firststorage electrode 133 a, second storage electrode 133 b, third storageelectrode 133 c, and fourth storage electrode 133 d) may be modified invarious ways.

The data voltage applied to the data line 171 may continuously changewith time, which influences the voltage of the first subpixel electrode191 a, the second subpixel electrode 191 b, and the third subpixelelectrode 191 c. The first storage electrode 133 a, the third storageelectrode 133 c, and the fourth storage electrode 133 d may partiallyoverlap the subpixel electrodes (first subpixel electrode 191 a, secondsubpixel electrode 191 b, and third subpixel electrode 191 c,) adjacentto the data line, such that they can avoid the influence of the voltage.

In an example, an alignment layer may be formed on the first substrateand the second substrate of the liquid crystal layer, and it may bepossible to align light in order to control the alignment direction andthe alignment angle of the liquid crystal by radiating light to thealignment layers. Although it may be possible to increase the apertureratio and improve the response speed of the liquid crystal by means ofthe light alignment, the alignment directions of the liquid crystal maybe different at the interfaces of difference domains, such that texturemay be generated at the interfaces.

The portion indicated by B in FIG. 5 is the region where the texture isgenerated, in which luminance may be larger than the other regions.However, it may be possible to reduce the influence caused by thegeneration of texture. In an example, if the liquid crystal is disposedat an angle of 0 degree at the longitudinal line portion crossing thecenter of the subpixel electrodes (first subpixel electrode 191 a, thesecond subpixel electrode 191 b, and third subpixel electrode 191 c),the longitudinal line portion may be shown as if a luminance differencefrom the other regions is not large, if seen from the sides and thefront. On the contrary, if the liquid crystal is disposed at an angle of90 degrees at the transverse line portion crossing the centers of thesubpixel electrodes (first subpixel electrode 191 a, the second subpixelelectrode 191 b, and the third subpixel electrode 191 c), the transverseline portion may be shown as if a luminance difference from the otherregions is large, if seen from the sides.

Therefore, it may possible to reduce an influence of voltage due totexture by forming the second storage electrode 133 b, the secondstorage electrode lines 131 b to cover the transverse line portioncrossing the centers of the subpixel electrodes (first subpixelelectrode 191 a, second subpixel electrode 191 b, and third subpixelelectrode 191 c).

Unlike the first exemplary embodiment, a light blocking membercorresponding to the third pixel electrode 191 c is not formed on thesecond substrate, in the second exemplary embodiment. That is, the thirdsubpixel electrode 191 c may reduce the voltage of the second subpixelelectrode 191 b, as well as display an image by transmitting light.

In the second exemplary embodiment, the voltages of the second subpixelelectrode 191 b and the third subpixel electrode 191 c may be similar ornear identical, while the voltage of the first subpixel electrode 191 amay be larger than the voltage of the second subpixel electrode 191 band the third subpixel electrode 191 c. That is, although one pixel isdivided in three subpixels, two subpixels may have the similar or nearidentical voltage, such that two grays may be implemented. In thisconfiguration, the side visibility is further improved by applying threedifferent voltages to the three subpixels, and a voltage difference inthe second subpixel electrode 191 b and the third subpixel electrode 191c is described hereafter with reference to the third exemplaryembodiment.

A liquid crystal display according to the third exemplary embodiment ofthe invention is described hereafter in detail with reference to FIG. 6,FIG. 7, FIG. 8, and FIG. 9.

FIG. 6 is a layout view of a lower display panel of a liquid crystaldisplay according to an exemplary embodiment of the invention. FIG. 7 isa cross-sectional view of the liquid crystal display according anexemplary embodiment of the invention, taken along the line VII-VII′ ofFIG. 6. FIG. 8 is a cross-sectional view of the liquid crystal displayaccording to an exemplary embodiment of the invention, taken along theline VIII-VIII′ of FIG. 6. FIG. 9 is a cross-sectional view of a liquidcrystal display according to a modification of an exemplary embodimentof the invention, taken along the line VIII-VIII′ of FIG. 6.

A large portion of the configuration of the liquid crystal displayaccording the third exemplary embodiment of the invention is similar tothe liquid crystal display according to the second exemplary embodiment,as shown in FIG. 6. Therefore, the detailed description is not providedand discussion will be directed towards the differences.

In the liquid crystal display according to the third exemplaryembodiment of the invention, a first subpixel electrode 191 a and asecond subpixel electrode 191 b may be formed in the same way as in theliquid crystal display according to the second exemplary embodiment. Oneor more fine slits 193 may be provided in the third subpixel electrode191 c. It is possible to make the voltage of the third subpixelelectrode 191 c lower than the voltage of the second subpixel electrode191 b by providing the fine slits 193.

As shown in FIG. 7, a gate insulating layer 140 and a passivation layer180 are sequentially stacked on the first substrate 110 and the thirdsubpixel electrode 191 c is formed on the passivation layer 180. Acommon electrode 270 is formed on the second substrate 210 opposite tothe first substrate 110.

The fine slits 193 may be provided at regular intervals with variouswidths. In an example, the width ‘a’ of a strip of the third subpixelelectrode 191 c between adjacent fine slits 193 may have a width rangeof 1 μm to 4 μm. Further, the width ‘b’ of the fine slit 193 may be inthe range of 1 μm to 5 μm.

Further, as shown in FIG. 8, the thickness ‘d’ of the passivation layer180 under the third subpixel electrode 191 c may be larger than thethickness ‘c’ of the passivation layer under the first subpixelelectrode 191 a and the second subpixel electrode 191 b. (Please notethat only the second subpixel electrode 191 b is illustrated in FIG. 8,since the structure around the first subpixel electrode 191 a is thesame as that around the second subpixel electrode 191 b.) That is, itmay be possible to form the passivation layers 180 to have differentthicknesses in accordance with the positions. In an example, thethickness may be adjusted by using a slit mask of a halftone mask in theprocess of forming the passivation layers 180, even without using anadditional mask.

It may be possible to further increase the difference in voltage betweenthe third subpixel electrode 191 c and the second subpixel electrode 191b by making the thickness of the passivation layer 180 irregular suchthat the cell gap between the first substrate 110 and the secondsubstrate 210 is different in accordance with their positions, asdescribed above. In this configuration, the cell gap ‘f’ at the portionwhere the third subpixel electrode 191 c is formed may be smaller at 0.1μm to 0.5 μm than the cell gap ‘e’ at the portion where the secondsubpixel electrode 191 b is formed.

As shown in FIG. 9, alignment layers 11 a and 21 may be formed on thefirst substrate 110 and the second substrates 210 of the liquid crystaldisplay according to the third exemplary embodiment of the invention.Also, it may be possible to align light in order to control thealignment direction and the alignment angle of the liquid crystal byradiating light to the alignment layer.

The pretilt angle of the alignment layer 11 b at the portioncorresponding to the third subpixel electrode 191 c may be smaller thanthe pretilt angle of the alignment layer 11 a at the portioncorresponding to the second subpixel electrode 191 b. This difference inpretilt angles may allow further increases in the voltage differencebetween the third subpixel electrode 191 c and the second subpixelelectrode 191 b. In an example, the pretilt angle of the alignment layer11 b at the portion corresponding to the third subpixel electrode 191 cmay be smaller at 0.5 degrees to 2 degrees than the pretilt angle of thealignment layer 11 a at the portion corresponding to the second subpixelelectrode 191 b.

In the liquid crystal display according to the third exemplaryembodiment, a method of providing the fine slits 193 in the thirdsubpixel electrode 191 c, a method of making the cell gap different byadjusting the height of the passivation layers 180 to be different, anda method of providing the pretilt angle different in light alignment hasbeen described in order to making a difference in voltage between thesecond subpixel electrode 191 b and the third subpixel electrode 191 c.One of the three methods may be used alone or in conjunction with theone or two of the other described methods.

In the liquid crystal display according to the third exemplaryembodiment, three grays may be implemented by making a difference involtage between the second subpixel electrode 191 b and the thirdsubpixel electrode 191 c such that the subpixel electrodes (firstsubpixel electrode 191 a, the second subpixel electrode 191 b, and thethird subpixel electrodes 191 c) have different voltages. As a result,the side visibility can be more improved over the second embodimenthaving one pixel shown in two grays, if one pixel is shown with threegrays, as in the third exemplary embodiment.

A liquid crystal display according to a fourth exemplary embodiment ofthe invention is described hereafter in detail with FIG. 10, FIG. 11,and FIG. 12.

FIG. 10 is an equivalent circuit diagram of one pixel of a liquidcrystal display according to an exemplary embodiment of the invention.FIG. 11 is a layout view of a lower display panel of the liquid crystaldisplay according to an exemplary embodiment of the invention. FIG. 12is a cross-sectional view of the liquid crystal display according to anexemplary embodiment of the invention, taken along the line XII-XII′ ofFIG. 11.

A large portion of the configuration of the liquid crystal displayaccording the fourth exemplary embodiment of the invention is similar tothe liquid crystal display according to the second exemplary embodiment,as shown in FIG. 10. Therefore, the detailed description is not providedand the discussion will be directed towards the differences.

In the liquid crystal display according to the fourth exemplaryembodiment of the invention, the third liquid crystal capacitor Clcc isnot directly connected to the third switching element Qc, but connectedthrough a transforming capacitor Ct. That is, the liquid crystal displayaccording to the fourth exemplary embodiment may further include thetransforming capacitor Ct, as compared with the liquid crystal displayaccording to the second exemplary embodiment. The transforming capacitorCt is connected to the third switching element Qc and the third liquidcrystal capacitor Clcc is connected to the transforming capacitor Ct.

If gate-on voltage is applied to the first gate line GLn, the firstswitching element Qa and the second switching element Qb are turned on.Also, the same data signal is applied through the data line DL, suchthat the first liquid crystal capacitor Clca and the second liquidcrystal capacitor Clcb are charged with similar or near identicalvoltage. Thereafter, if gate-on voltage is applied to the second gateline GLn+1, which is the next gate line, the third switching element Qcis turned on and some of the charged voltage of the second liquidcrystal capacitor Clcb are discharged to the transforming capacitor Ctand the third liquid crystal capacitor Clcc. Therefore, a difference involtage is created between the first liquid crystal capacitor Clca andthe second liquid crystal capacitor Clcb. Further, the voltagedischarged from the second liquid crystal capacitor Clcb may be dividedto the transforming capacitor Ct and the third liquid crystal capacitorClcc, such that a difference in voltage is created between the secondliquid crystal capacitor Clcb and the third liquid crystal capacitorClcc. Accordingly, it may be possible to improve the side visibility ofthe liquid crystal display.

The structure of the liquid crystal display according to the fourthexemplary embodiment of the invention, as shown in FIG. 11, has a largeportion similar to the configuration of the liquid crystal displayaccording to the second exemplary embodiment. Therefore, the detaileddescription is not provided and the discussion will be directed towardsthe differences.

In the liquid crystal display according to the fourth exemplaryembodiment of the invention, unlike the second exemplary embodiment, thethird subpixel electrode 191 c is not directly connected to the thirddrain electrode 175 c.

As shown in FIG. 12, a gate insulating layer 140 is formed on the firstsubstrate 110 and a third drain electrode 175 c is formed on the gateinsulating layer 140. A passivation layer 180 is provided between thethird drain electrode 175 c and the third subpixel electrode 191 c toform the transforming capacitor Ct. A common electrode 270 is formed onthe second substrate 210 opposite to the first substrate 110. A liquidcrystal layer (not shown) is formed between the third subpixel electrode191 c and common electrode 270 to form the third liquid crystalcapacitor Clcc.

The third drain electrode 175 c may be formed to have a size above areference level to function as the transforming capacitor Ct. Further,the third drain electrode 175 c may generally be an opaque electrode,such that it is possible to reduce the aperture ratio of the thirdsubpixel electrode 191 c.

In this configuration, it may be possible to make the thickness ‘h’ ofthe passivation layer 180 (at the portion where the third drainelectrode 175 c and the third subpixel electrode 191 c overlap) smallerthan the thickness ‘g’ of the passivation layer 180 (at the portionwhere the third drain electrode 175 c and the third subpixel electrode191 c do not overlap), in order to reduce the size of the third drainelectrode 175 c and increase the capacitance of the transformingcapacitor Ct. That is, it may be possible to form the passivation layer180 to have irregular thickness in accordance with their positions byusing a slit mask or a halftone mask in the process of forming thepassivation layer 180, even without using an additional mask.

In the liquid crystal display according to the fourth exemplaryembodiment, the side visibility may be improved by creating a differencein voltage levels between the second subpixel electrode 191 b and thethird subpixel electrode 191 c. Such a difference in voltage levels maybe provided using the transforming capacitor (Ct in FIG. 11) such thatthe first subpixel electrode 191 a, the second subpixel electrode 191 b,and the third subpixel electrode 191 c have different voltages. As aresult, three shades of grays may be implemented.

A liquid crystal display according to a fifth exemplary embodiment ofthe invention is described hereafter in detail with FIG. 13 and FIG. 14.

FIG. 13 is an equivalent circuit diagram of one pixel a liquid crystaldisplay according to an exemplary embodiment of the invention. FIG. 14is a layout view of a lower display panel of the liquid crystal displayaccording to an exemplary embodiment of the invention.

A large portion of the configuration of the liquid crystal displayaccording the fifth exemplary embodiment of the invention is similar tothe liquid crystal display according to the fourth exemplary embodiment,as shown in FIG. 13. Therefore, the detailed description is not providedand discussion will be directed towards the differences.

In the liquid crystal display according to the fifth exemplaryembodiment of the invention, unlike the liquid crystal display accordingto the fourth exemplary embodiment, the second gate line is not providedbut the first gate line GLn is provided and connected to a firstswitching element Qa and a second switching element Qb. The first gateline GLn and the second gate line are not discriminated, such that thefirst gate line GLn will be described as a gate line in the claim(s)relating to the fifth exemplary embodiment.

As shown in FIG. 13, the third switching element Qc is not connected toa specific gate line, a control terminal N1 is floated, an inputterminal N3 is connected to the second switching element Qb, and anoutput terminal N2 is connected to the transforming capacitor Ct.Further, the transforming capacitor Ct is connected to the third liquidcrystal capacitor Clcc.

If gate-on voltage is applied to the first gate line GLn, the firstswitching element Qa and the second switching element Qb connectedthereto are turned on. Further, the same data signal may be appliedthrough the data line DL, such that the first liquid crystal capacitorClca and the second liquid crystal capacitor Clcb are charged withsimilar or near identical voltages.

As positive data voltage is applied through the data line DL, thevoltage of the control terminal N1 may increase while the input terminalN3 of the third switching element Qc is charged with positive datavoltage. Accordingly, current flows from the input terminal N3 to theoutput terminal N2 of the third switching element Qc and the voltage ofthe output terminal N2 correspondingly may increase.

If gate-off voltage is applied to the first gate line GLn, the currentcontinues flowing from the input terminal N3 to the output terminal N2,until the voltage of the output terminal N2, the voltage of the inputterminal N3, and the voltage of the control terminal N1 become thesimilar or near identical in the third switching element Qc.Accordingly, the voltage of the input terminal N3 may decrease and thevoltage of the output terminal N2 may increase. As a result, the voltageof the second liquid crystal capacitor Clcb connected to the inputterminal N3 of the third switching element Qc decreases under thepositive data voltage that has been applied, such that it decreasesunder the voltage of the first liquid crystal capacitor Clca. Further,the voltage discharged from the second liquid crystal capacitor Clcb isdivided to the transforming capacitor Ct and the third liquid crystalcapacitor Clcc, such that a difference in voltage is generated betweenthe second liquid crystal capacitor Clcb and the third liquid crystalcapacitor Clcc. Accordingly, it may be possible to improve the sidevisibility of the liquid crystal display.

The structure of the liquid crystal display according to the fifthexemplary embodiment of the invention, as shown in FIG. 14, has a largeportion similar to the configuration of the liquid crystal displayaccording to the fourth exemplary embodiment; therefore, the detaileddescription is not provided and discussion will be directed towards thedifferences.

In the liquid crystal display according to the fifth exemplaryembodiment of the invention, unlike the fourth exemplary embodiment, thesecond gate line is not specifically provided and but the first gateline 121 a is provided.

The third gate electrode 124 c is floated between the second subpixelelectrode 191 b and the third subpixel electrode 191 c, without beingconnected to a specific gate line.

Further, similar to the fourth exemplary embodiment, it is possible tomake the thickness of the passivation layer 180 at the portion where thethird drain electrode 175 c and the third subpixel electrode 191 coverlap smaller than the other portions.

In the liquid crystal display according to the fifth exemplaryembodiment, it may be possible to improve the side visibility by makinga difference in voltage between the second subpixel electrode 191 b andthe third subpixel electrode 191 c. Such a difference may be createdusing the third switching element (Qc in FIG. 13) with the controlterminal floating and the transforming capacitor (Ct in FIG. 13) suchthat the subpixel electrodes (first subpixel electrode 191 a, secondsubpixel electrode 191 b, and third subpixel electrode 191 c) havedifferent voltages and three grays are implemented as a result.

A liquid crystal display according to a sixth exemplary embodiment ofthe invention is described hereafter in detail with reference to FIG.15.

FIG. 15 is an equivalent circuit diagram of one pixel a liquid crystaldisplay according to an exemplary embodiment of the invention.

A liquid crystal display according to the sixth exemplary embodiment ofthe invention, as shown in FIG. 15, includes a first switching elementQa and a second switching element Qb, a first liquid crystal capacitorClca connected to the first switching element Qa, a second liquidcrystal capacitor Clcb and a third liquid crystal capacitor Clccconnected to the second switching element Qb, and a third switchingelement Qc connected to the second switching element Qb.

Further, a first transforming capacitor Ct1 may be further formedbetween the second switching element Qb and the third liquid crystalcapacitor Clcc. Also, a second transforming capacitor Ctz connected tothe third switching element may be further formed.

The liquid crystal display according to the sixth exemplary embodimentof the invention further includes a first gate line GLn, a second gateline GLn+1, and a data line DL. The first switching element Qa and thesecond switching element Qb may be three terminal elements of a thinfilm transistor etc., connected to the first gate line GLn to beswitched by the same signal, and connected to the data line DL toreceive the same data signal. The third switching element Qc may be athree terminal element of a thin film transistor etc., and connected tothe second gate line GLn+1.

If gate-on voltage is applied to the first gate line (GLn), the firstswitching element Qa and the second switching element Qb are turned onand the same data signal is applied through the data line DL, such thatthe first liquid crystal capacitor Clca and the second liquid crystalcapacitor Clcb are charged with the similar or near identical voltage.The third liquid crystal capacitor Clcc is charged with voltage lowerthan the first liquid crystal capacitor Clca and second liquid crystalcapacitor Clcb, due to the first transforming capacitor Ct1.

Thereafter, if gate-on voltage is applied to the second gate line GLn+1,which is the next gate line, the third switching element Qc is turned onand some of the charged voltage of the second liquid crystal capacitorsClcb and third liquid crystal capacitor Clcc is discharged to the secondtransforming capacitor Ctz. Therefore, the voltage of the second liquidcrystal capacitor Clcb decreases under the voltage of the first liquidcrystal capacitor Clca and the voltage of the third liquid crystalcapacitor Clcc decreases under the voltage of the second liquid crystalcapacitor Clcb. Accordingly, it may be possible to improve the sidevisibility of the liquid crystal display.

Although the structure of the liquid crystal display according to thesixth exemplary embodiment of the invention is not shown, it may includea first substrate, one or more first gate lines and second gate linesand one or more data lines formed on the first substrate, a firstswitching element and a second switching element connected to the firstgate line and the data line, a first subpixel electrode connected to thefirst switching element, a second subpixel electrode and a thirdsubpixel electrode connected to the second switching element, a firsttransforming capacitor formed between the second switching element andthe third subpixel electrode, a third switching element connected to thesecond switching element and switched by the second gate line, and asecond transforming capacitor connected to the third switching element.

Further, it may further include a second substrate opposite to the firstsubstrate, a common electrode formed on the second substrate, and aliquid crystal layer formed between the first substrate and the secondsubstrate.

In the liquid crystal displays according to the third to sixth exemplaryembodiments of the invention, the first subpixel electrode 191 a, thesecond subpixel electrode 191 b, and the third subpixel electrode 191 chave different voltages and three grays may be implemented as a result,thereby improving the side visibility.

Hereinafter, the maximum area ratio and voltage ratio of the subpixelelectrodes (first subpixel electrode 191 a, second subpixel electrode191 b, and third subpixel electrode 191 c) for improving the sidevisibility of the liquid crystal displays according to the third tosixth exemplary embodiments of the invention are described withreference to FIG. 16, FIG. 17, FIG. 18, and FIG. 19.

FIG. 16 is a graph showing a V-T curve at the front and the side of aliquid crystal display according to the related art. FIG. 17 is a graphshowing a V-T curve at the front and the side of a liquid crystaldisplay according to an exemplary embodiment of the invention. FIG. 18is a graph showing a V-T curve at the front and the side of a liquidcrystal display according to an exemplary embodiment of the invention.FIG. 19 at the front and the side of a liquid crystal display accordingto an exemplary embodiment of the invention.

In FIG. 16, FIG. 17, FIG. 18 and FIG. 19, the horizontal axis representsdata voltage, the vertical axis represents transmittance, the solid linerepresents the front visibility, and the dotted line represents the sidevisibility.

A liquid crystal display according to the related art may have a problemin that, as shown in FIG. 16, bumping may be generated at a time when apixel electrode where voltage showing a low gray is applied is turnedon, if the difference between the voltage showing a high gray and thevoltage showing a low gray is large in the method of dividing one pixelin two subpixels and applying different voltages thereto.

In the liquid crystal display according to an exemplary embodiment ofthe invention, as shown in FIG. 17, FIG. 18 and FIG. 19, the sectionwhere the bumping period, as shown in FIG. 16, is removed by dividingone pixel in three subpixels with different voltages.

FIG. 17, FIG. 18, and FIG. 19 show several typical experimentalexamples, in which the voltage ratio of the first subpixel electrode,second subpixel electrode, and third subpixel electrode may be 1:0.6 to0.85:0.4 to 0.7. Further, the area ratio of the first subpixelelectrode, second subpixel electrode, and third subpixel electrode maybe 1:1 to 2:1 to 2. While the voltage ratio and the area ratio may notbe limited to the exemplary ratios provided, the effect of improving thevisibility may be low if the voltage ratio and the area ratio are toosmall, and a bumping section may be generated if the voltage ratio andthe area ratio are too large.

It will be apparent to those skilled in the art that variousmodifications and variation can be made in the present invention withoutdeparting from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A liquid crystal display, comprising: a firstsubstrate; a first gate line, a second gate line, and a data line formedon the first substrate; a first switching element and a second switchingelement connected to the first gate line and the data line; a firstsubpixel electrode connected to the first switching element; a secondsubpixel electrode and a third subpixel electrode connected to thesecond switching element; a first transforming capacitor formed betweenthe second switching element and the third subpixel electrode; a thirdswitching element connected to the second switching element andconfigured to be switched by a signal received from the second gateline; a second transforming capacitor connected to the third switchingelement; a second substrate; a common electrode formed on the secondsubstrate; and a liquid crystal layer formed between the first substrateand the second substrate, wherein the first switching element isdirectly connected to the data line.
 2. The liquid crystal display ofclaim 1, wherein, in response to the third switching element beingswitched by the signal received from the second gate line, the voltageof the first subpixel electrode is higher than the voltage of the secondsubpixel electrode, and the voltage of the second subpixel electrode ishigher than the voltage of the third subpixel electrode.
 3. The liquidcrystal display of claim 2, wherein a voltage ratio of the firstsubpixel electrode to the second subpixel electrode is 1:0.6-0.85, and avoltage ratio of the first subpixel electrode to the third subpixelelectrode is 1:0.4-0.7.
 4. The liquid crystal display of claim 2,wherein an area ratio of the first subpixel electrode to the secondsubpixel electrode is 1:1-2, and an area ratio of the first subpixelelectrode to the third subpixel electrode is 1:1-2.